TROPICAL WEATHER OUTLOOK SYNOPSIS…DISTURBED WEATHER FORMS IN THE SW CARIBBEAN…ISSUED MAY 18, 2022…7:50 P. M. EDT

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(T. F. “Storm” Walsh)

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Please be aware, even though I do not post every night, rest assured I am continuously monitoring various areas for any significant weather.  I will be taking Sundays off (family time), unless we have active systems that may be posing a threat (i.e. Tropical, Winter Weather, Coastal Storms, etc.).

I will reiterate, my forecasts are based on the available information at the time of analysis, and are only as accurate as the information analyzed and the solutions provided.

Good evening everyone!

From here on out, I will be moving away from severe weather forecasts, unless the threat is forecast to produce an outbreak, or significant tornadoes.  Then, I’ll break from tropical weather and report on any severe weather.  Again, please remember, my forte and specialty is tropical storms and hurricanes.  Given I work until late afternoon, I cannot analyze and write a synopsis for both.  I will post the SPC link for you to visit and stay updated on any severe weather threat.  Thanks for your understanding.
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https://www.spc.noaa.gov/classic.html

For the past week, I have mentioned the CAG or Central American Gyre, in which I had also outlined it in the GFS 850 mb wind analysis.  You may remember this:

The following will explain the CAG (Central American Gyre).
Here is an article from WBRZ news explaining the CAG:
https://www.wbrz.com/news/the-central-american-gyre-and-tropical-formation/

Please remember you heard it here first, as the NHC just mentioned it today in the Tropical Weather Discussion.  From the NHC:

…SPECIAL FEATURES…
Global models continue to suggest a Central American Gyre (CAG) forming near the western Caribbean by Fri, and then gradually shifting westward across Central America through early next week. CAG tends to enhance SW monsoon flow, and lift the monsoon trough well north of its typical position. This will increase convergent surface winds and advect abundant moisture northward, triggering widespread strong convection over Central America. Expect heavy rainfall from the southern parts of Guatemala and Honduras, southward to Panama. Extreme rainfall is possible near the Pacific coast of these countries, and also over southern Honduras and NE Nicaragua. This will increase the potential for flooding, especially near valleys in mountainous terrain. Please refer to products issued by your local weather service for more information.

Now on with the synopsis.

An area of disturbed weather has developed in the SW Caribbean Sea.  Analysis of satellite imagery animations tends to indciate a slight rotation.  Analysis of recent vorticity maps indicates rotation is probably limited to the mid levels of the atmosphere, as the 700 mb and 500 mb vorticity maps show vorticity only at these levels at the moment.
WEATHERNERDS GOES 16 SATELLITE LOOP IMAGERY (IR, VIS, AND SWIR)



CIMSS 700 MB AND 500 MB VORTICITY MAPS


Analysis of the recent wind shear map shows wind shear over the area on the order of 20-30 kts, which is on the lower end of being non conducive for development at the moment.  However, both the ECMWF and GFS wind shear forecast maps indicate shear may weaken during the next 42 hours, before favorable conditions shift west over the Central American landmass.  Analysis of the current upper level wind pattern (200 mb) still indicates a favorable upper level outflow pattern.  Based on the forecast, this pattern is also forecast to remain favorable for the next 42-48 hours, before shifting toward the west over land, and eventually the extreme EPAC.
CIMSS WIND SHEAR MAP

ECMWF 200 MB PATTERN FORECAST

Analysis of RH values at 500 mb, and surface TPW maps, indicate moisture to remain favorable during the next 72 hours, before shifting to the EPAC.
TPW ANIMATION

500 MB RELATIVE HUMIDITY ANIMATION

The ECMWF EPS Tropical Cyclone Probability model has lowered its probability of a T.D. forming, and has shifted the higher probs west, into the EPAC.  It is noted that on the latest run of the GFS, the model has dropped development over the next 10 days.
ECMWF EPS TROPICAL CYCLONE PROBABILITY ANIMATION

This area of showers and thunderstorms appears to be moving very slowly at the moment, toward the WNW or just north of west.  Steering currents are presently weak, making it a little more difficult to get a solid direction on this.  The ECMWF Prob. forecast indicates a westward motion into the EPAC, while analysis of forecast steering currents indicates more of a WNW motion soon.  Given this discrepancy, it’s kind of an unknown as to whether further development of this area will occur, as it will depend on EXACTLY where this moves.  Right now, in my professional opinion, based on the forecast favorable conditions, this area of disturbed weather could become better defined during the next 48 hours, before conditions become less favorable.  In other words, there is no definite solution on this at the moment, given the uncertainty in direction of travel over the next 48 hours.  I will perform another analysis tomorrow evening to see if any significant changes occur to forecast conditions, and future steering currents.

You may direct any questions by contacting me personally, ANYTIME, at: twalsh22000@yahoo.com

Have a blessed evening!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST